ruler

noun

rul·​er ˈrü-lər 

1

: one that rules

specifically : sovereign

2

: a worker or a machine that rules paper

3

: a smooth-edged strip (as of wood or metal) that is usually marked off in units (such as inches) and is used as a straightedge or for measuring

rulership

ˈrü-lər-ˌship 

noun

Synonyms of ruler

• monarch
• emperor
• sovereign
• king

Examples of ruler in a Sentence

a summit attended by a number of rulers from around the world

This ruler shows inches and centimeters.

Recent Examples on the Web

Nearly ninety thousand square kilometers of northeast China, an area larger than all of contemporary Primorye, was set aside for warriors to pursue game and demonstrate skills before their ruler. —Literary Hub, 14 Nov. 2025

Olmec sculptures often glorified rulers and gods. —New Atlas, 14 Nov. 2025

The various sentences are written to Xerxes I, ruler of the Achaemenid Empire from 486 to 465 BCE. —Andrew Paul, Popular Science, 12 Nov. 2025

With war looming and chaos consuming the kingdom —drawing in the ruthless kings of other Scandinavian countries and even a powerful English ruler — the stage is set for a thundering, cataclysmic, compelling, and utterly magical new Norse saga. —Matt Grobar, Deadline, 11 Nov. 2025

Word History

First Known Use

14th century, in the meaning defined at sense 1

Phrases Containing ruler

• co-ruler

Rhymes for ruler

• cooler
• jeweller
• schooler
• schuller
• preschooler
• vestibular

Kids Definition

ruler

noun

rul·​er ˈrü-lər 

1

: sovereign entry 1 sense 1

2

: a straight strip of material (as wood or metal) marked off in units and used as a guide in drawing lines or for measuring